I remember getting a taxi with Jaap...

I KNEW it would turn out to be a horrible mistake. For the past month or so, I've been trying to cut down on my drinking by having one glass of water for every glass of wine I consume. But now I see that what I should have been doing was giving my liver a workout for the festive season. Not that it feels very festive right now. Let me explain.

Yesterday was our team Christmas lunch. Rory had booked the private dining- room in a smart restaurant that I've been meaning to try out, one of those fashionable ones with a one-word name like "Neptune" or "Grocery". Anyway, I was dreading it. Not because of the food, you understand, but because of Jaap.

Ever since I found out it was he who organised my get-well-soon flowers when I had flu the other week, I haven't been able to relax in the office. I get butterflies every time he so much as glances in my direction, and when he stands next to my desk to discuss some deal or other I can hardly breathe. A waft of his aftershave makes me go weak at the knees, and if we meet by the coffee machine I'm so nervous I can't speak. It's absurd. Here I am, 25 years old, and I'm behaving like some silly teenager.

Anyway, there was no escaping the lunch and I was glad I hadn't. Heavenly food, and I managed to relax for the first time in days thanks to several spectacular Bloody Marys and a fair measure of champagne. In fact, it all went so well we went on to some drinking place when we'd finished in the restaurant and had a few more refreshments. And suddenly it was 10pm and we'd been drinking for hours and I realised I wanted to go home. The last thing I remember is getting into a taxi and Jaap climbing in after me. After that it's a blank.

I woke up this morning with a vile hangover, one of those ones where you hardly dare open your eyes in case your brain slides out of the sockets. I vowed there and then never to touch another drop of alcohol, as you always do when you have a hangover, and stumbled out of bed to fetch a glass of water and some Resolve. That's when I saw it, of course: a man's watch on the bedside table.

I tried desperately to remember anything after getting into the taxi last night with Jaap, but I couldn't. He must have come back here. That was the only possible explanation. We came back here and we... oh God, please, not that! And now I had to go into the office and see him. I sat on the bed, clutching my head, trying to decide which was worse, the hangover or the shame. I could have wept.

I felt every lurch of the Tube as I struggled bravely into the office, my insides like jelly. So it was a relief to find I was the first one in. That would give me a few minutes at least to compose my mind. But I'd hardly sat down when the phone rang, and it was Olivier. Olivier, my boyfriend. All the shame and horror came flooding back. I had got legless and cheated on my boyfriend after an office party. How hideously, hideously tacky.

"Are you all right?" he asked. "You sound terrible."

"I feel terrible," I told him. "I never want another drink again ever."

He laughed. "You're not the only one. The other morning I was so hungover I lost my watch somewhere. I didn't leave it at your place, did I?"

Olivier's watch. Olivier's watch, not Jaap's. Oh, what a relief.

I'm still giving up alcohol, though.